Rotating equipment such as compressors include a motor-driven shaft that drives a rotatable component such as an impeller for pumping a fluid such as a gas or other type of processed fluid. Such mechanical seals typically include opposed pairs of relatively rotatable seal rings which are supported in a seal housing and are mounted in surrounding relation to the equipment shaft. One seal ring remains stationary while the other seal ring is fixedly mounted on the shaft so as to rotate therein wherein the seal rings are relatively rotatable and have opposed interfacing seal faces which define a sealing region that prevent or greatly minimizes the leakage of process fluid across the sealing region.
Mechanical seals can be provided in various combinations including double and tandem configurations. In dry gas mechanical seals of this type, a buffer fluid can be provided outboard of the seal rings, and additionally a seal supply gas can be supplied to the region adjacent the seal faces. During shaft rotation, a thin fluid film forms between the seal faces to separate the seal faces and provide dry gas, non-contacting operation of the mechanical seal.
In various mechanical seal configurations, the separation of the seal faces may allow for a process fluid located adjacent the seal rings to leak past the seal interface. However, discharge of such process fluid into the atmosphere is highly undesirable, and therefore, the invention relates to a recovery system for recovering any leakage across the seal rings to thereby prevent seal leakage from leaking to the ambient environment.
In particular, the invention relates to a leakage recovery system which collects any seal leakage gas from one or more dry gas seals in a recovery system, pressurizes such seal leakage, and returns the seal leakage to the compressor system at a point in the compressor system wherein the seal leakage can be used as a supply gas provided adjacent the inboard process side of the mechanical seal rings or alternatively, provided to the suction side of the compressor.
Other objects and purposes of the invention, and variations thereof, will be apparent upon reading the following specification and inspecting the accompanying drawings.
Certain terminology will be used in the following description for convenience and reference only, and will not be limiting. For example, the words “upwardly”, “downwardly”, “rightwardly” and “leftwardly” will refer to directions in the drawings to which reference is made. The words “inwardly” and “outwardly” will refer to directions toward and away from, respectively, the geometric center of the arrangement and designated parts thereof. Said terminology will include the words specifically mentioned, derivatives thereof, and words of similar import.